/* ===================

AX2E (AXESCON XACML 2.0 Engine) is the Java authorization engine, which implements OASIS XACML 2.0 standard.
Copyright (C) 2007 AXESCON LLC

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA


Contact: AXESCON LLC - info{at}axescon.com

 =================== */
/*
 * XML Type:  ExpressionImpl
 * Namespace: urn:oasis:names:tc:xacml:2.0:policy:schema:os
 * Java type: ExpressionImpl
 *
 * Automatically generated - do not modify.
 */
package axescon.xacml.model.policy;

import axescon.xacml.api.*;
import axescon.xacml.model.ctx.XacmlCtx;


/**
 * @author argyn
 * Responsibilities: represents XACML Policy schema element Expression
 * (@urn:oasis:names:tc:xacml:2.0:policy:schema:os).
 * <p/>
 *
 */
public interface Expression extends PolicyModelObject {

    /**
     * evaluates this expression
     * @param ch context handler
     * @param req request
     * @param pdp policy evaluator
     * @return result
     * @throws XacmlException
     * @throws ExpressionEvalIndeterminateException
     */
    Liquid eval(CtxHandler ch, XacmlCtx req, ExpressionEvaluator pdp)
            throws XacmlException, ExpressionEvalIndeterminateException;

    /**
     * gets return result type. it's usually the subclass of AttributeValue class or
     * an array of this class.
     * @param ff function factory
     * @return Java type of result
     * @throws ExpressionEvalIndeterminateException
     */
    Class getReturnDataType(FnFactory ff) throws ExpressionEvalIndeterminateException;


}
